Plasma treatment unit

Abstract

The plasma processing apparatus of the present invention includes a plasma processing chamber, a substrate support, a lower electrode, an RF power supply, and an upper electrode assembly. The upper electrode assembly includes a gas diffusion plate, an insulating plate, and an upper electrode plate disposed between the gas diffusion plate and the insulating plate and having a plurality of first through holes and a plurality of second through holes. The insulating plate has an inner annular protrusion and an outer annular protrusion protruding downward from its lower surface. The insulating plate has a plurality of first gas inlet holes, a plurality of second gas inlet holes, and a plurality of third gas inlet holes.

Description

Technical Field

[0001] This invention relates to a plasma treatment apparatus. Prior Technology

[0002] Patent Document 1 discloses a configuration of a capacitively coupled plasma processing apparatus having an electromagnet assembly disposed above or above a chamber. The capacitively coupled plasma processing apparatus of Patent Document 1 has an upper electrode that also functions as a cluster ejector. The apparatus configuration of Patent Document 1 suppresses the localized increase in the processing speed of plasma processing within the central portion of the substrate. [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2021-44535 Summary of the Invention

[0004] [The problem the invention aims to solve]

[0005] The present invention improves the uniformity of plasma density distribution by partially altering the distribution of gas introduced into the plasma processing chamber. [Technical means to solve the problem]

[0006] One embodiment of the present invention is a plasma processing apparatus, comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber; a lower electrode disposed within the substrate support; at least one RF power supply coupled to the lower electrode; and an upper electrode assembly disposed above the substrate support; the upper electrode assembly comprising: a gas diffusion plate having at least one first gas supply port for a first gas and at least one second gas supply port for a second gas; an insulating plate; and an upper electrode plate disposed between the gas diffusion plate and the insulating plate, and having a plurality of first through holes communicating with the at least one first gas supply port and a plurality of second through holes communicating with the at least one second gas supply port; The aforementioned insulating plate has an inner annular protrusion and an outer annular protrusion protruding downward from its lower surface. The insulating plate has: a plurality of first gas inlet holes, which are formed on the inner annular protrusion, and each first gas inlet hole is connected to the at least one first gas supply port through any of the plurality of first through holes; a plurality of second gas inlet holes, which are formed on the outer annular protrusion, and each second gas inlet hole is connected to the at least one first gas supply port through any of the plurality of first through holes; and a plurality of third gas inlet holes, which are formed outside the second gas inlet holes, and each third gas inlet hole is connected to the at least one second gas supply port through any of the plurality of second through holes. [Effects of the Invention]

[0007] According to the present invention, the uniformity of plasma density distribution can be improved by partially changing the distribution of the gas introduced into the plasma processing chamber. Simple Explanation of the Diagram

[0008] Figure 1 is a schematic diagram illustrating the structure of a plasma processing system. Figure 2 is an enlarged illustration of one part of the upper electrode assembly. Figure 3A is a schematic diagram illustrating the structure of the insulating plate in the first embodiment. Figure 3B is a schematic plan view of the insulating plate according to the first embodiment. Figure 4 is a schematic diagram illustrating the structure of the insulating plate in the second embodiment. Figure 5 is a schematic diagram illustrating the structure of the insulating plate in the third embodiment. Figure 6 is a schematic diagram illustrating the structure of the insulating plate in the fourth embodiment. Figure 7 is a schematic diagram illustrating the structure of the insulating plate in the fifth embodiment. Figure 8 is a schematic diagram illustrating the structure of the insulating plate in the sixth embodiment. Figure 9 is a schematic diagram illustrating the structure of the insulating plate in the seventh embodiment. Figure 10 is a schematic diagram illustrating gas flow in one embodiment of the present invention. Figure 11 is a schematic diagram illustrating gas flow in one embodiment of the present invention. Figure 12 is a schematic diagram illustrating gas flow in one embodiment of the present invention. Figure 13 is a schematic diagram illustrating gas flow in one embodiment of the present invention. Implementation

[0009] In the manufacturing process of semiconductor devices, plasma is generated by exciting a processing gas supplied to a chamber, and various plasma processes such as etching, film formation, and diffusion are performed on a semiconductor substrate (hereinafter referred to as "substrate") supported by a substrate support. These plasma processes are performed, for example, using a capacitively coupled plasma (CCP) plasma processing apparatus, which includes an upper electrode assembly that forms at least a part of the gas diffusion section constituting the top (top plate) of the chamber.

[0010] For example, it is well known that when etching is performed using a mask in a plasma processing apparatus, even within the same process, the residual film condition of the mask, etc., sometimes differs between the periphery and the center of the substrate. To prevent such uneven residual film condition on the substrate, it is desirable to reduce byproducts (deposits) generated during etching and adhering to the upper electrode by homogenizing the processing gas introduced from the upper electrode assembly, which serves as a gas diffuser, or by introducing additional gas. By homogenizing the process, it is expected that the residual film condition of the mask, etc., will be uniformized, thus effectively advancing the etching process.

[0011] Furthermore, when etching is performed as a plasma process, there is a difference in plasma density between the periphery and the center of the substrate, resulting in uneven processing. Consequently, the size of the etched holes also becomes uneven; for example, the size of the etched holes at the periphery of the substrate may be smaller compared to the center. It is well known that in plasma processing apparatuses, additional gases are introduced in addition to the processing gas (etching gas) for various purposes such as protecting the inner walls. It is speculated that the uneven plasma density is due to the influence of the flow of these gases, and there is room for improvement in the configuration or structure of the gas inlet holes in the gas diffusion section.

[0012] However, the plasma processing apparatus described in Patent Document 1 focuses on the plasma processing speed in the substrate, and was invented specifically to address the problem of locally higher processing speeds at the center of the substrate. Patent Document 1 primarily discloses the technology of the lower electrode or its vicinity in the plasma processing apparatus, but does not reveal technical concepts related to the process uniformity of the gas diffusion section of the plasma processing apparatus. That is, in seeking to improve the uniformity of plasma processing on the substrate in the plasma processing apparatus, there is room for further improvement, particularly regarding the technology of the gas diffusion section or its vicinity.

[0013] Hereinafter, with reference to the drawings, an embodiment of a plasma processing system and a plasma processing method including the etching method of this embodiment will be described. Furthermore, in this specification and drawings, repeated descriptions are omitted because elements that have substantially the same functional configuration are labeled with the same symbols.

[0014] <Plasma Treatment System> First, the plasma treatment system of this embodiment will be described. Figure 1 is a schematic longitudinal sectional view showing the configuration of the plasma treatment system of this embodiment.

[0015] The plasma processing system includes a capacitively coupled plasma processing device 1 and a control unit 2. The plasma processing device 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. Furthermore, the plasma processing device 1 includes a substrate support unit 11 and a gas inlet unit. The substrate support unit 11 is disposed within the plasma processing chamber 10. The gas inlet unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet unit includes an upper electrode assembly 13. The upper electrode assembly 13 is disposed above the substrate support unit 11 and has an insulating plate 140 whose lower surface portion becomes a plasma exposure surface. In one embodiment, the upper electrode assembly 13 is disposed above the interior of the plasma processing chamber 10, for example, mounted on a ceiling plate 10b. An electromagnet unit 15 having a coil 15a inside is disposed above or on the upper part of the plasma processing chamber 10.

[0016] Inside the plasma processing chamber 10, a plasma processing space 10s is formed, defined by the upper electrode assembly 13, the top plate 10b, the sidewall 10a of the plasma processing chamber 10, and the substrate support portion 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s, and at least one gas outlet for discharging gas from the plasma processing space 10s. The sidewall 10a is grounded. The upper electrode assembly 13 and the substrate support portion 11 are electrically insulated from the plasma processing chamber 10.

[0017] The substrate support portion 11 includes a body portion 111 and a ring assembly 112. The upper surface of the body portion 111 has a central region 111a (substrate support surface) for supporting the substrate (wafer) W, and an annular region 111b (ring support surface) for supporting the ring assembly 112. The annular region 111b surrounds the central region 111a when viewed from above. The ring assembly 112 includes one or more annular members, at least one of which is an edge ring.

[0018] In one embodiment, the body portion 111 includes a base 113 and an electrostatic chuck 114. The base 113 includes a conductive member. The conductive member of the base 113 functions as a lower electrode. The electrostatic chuck 114 is disposed on the upper surface of the base 113. The upper surface of the electrostatic chuck 114 has the aforementioned central region 111a and an annular region 111b.

[0019] Furthermore, although the illustration is omitted, the substrate support portion 11 may also include a temperature regulation module configured to adjust at least one of the ring assembly 112, the electrostatic chuck 114, and the substrate W to a target temperature. The temperature regulation module may also include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid, such as brine or gas, flows through the flow path. Additionally, the substrate support portion 11 may also include a heat transfer gas supply portion configured to supply heat transfer gas (backside gas) between the back surface of the substrate W and the upper surface of the electrostatic chuck 114.

[0020] The gas supply unit 20 may also include at least one gas source 21 and at least one flow controller 22. In one embodiment, the at least one gas source 21 includes a main gas source 21a and an additive gas source 21b. In one embodiment, the gas supply unit 20 is configured to supply at least one processing gas from corresponding gas sources 21 to the upper electrode assembly 13 via corresponding flow controllers 22. The at least one processing gas includes a main gas and an additive gas. An example of a first gas in a main gas system and an example of a second gas in an additive gas system. In one embodiment, the gas supply unit 20 includes a main gas supply unit 20a for main gas and an additive gas supply unit 20b for additive gas. The main gas supply unit 20a is configured to supply the main gas from the main gas source 21a to the first gas supply port 13c of the upper electrode assembly 13 via the flow controller 22a. The gas supply unit 20b is configured to supply gas from the gas source 21b to the second gas supply port 14c of the upper electrode assembly 13 via a flow controller 22b. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may also include one or more flow modulation elements for modulating or pulsed flow of at least one process gas.

[0021] The power supply 30 includes an RF (radio frequency) power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive members (lower electrode) of the substrate support portion 11 and / or the conductive members (upper electrode) of the upper electrode assembly 13. Plasma is thus formed by at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least part of a plasma generation unit configured to generate plasma in the plasma processing chamber 10 from one or more processing gases. Furthermore, by supplying a bias RF signal to the lower electrode, a bias potential can be generated on the substrate W, thereby feeding the ionic components of the formed plasma into the substrate W.

[0022] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is configured to be coupled to a lower electrode and / or an upper electrode via at least one impedance matching circuit to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 160 MHz. In one embodiment, the first RF generating unit 31a may also be configured to generate a plurality of source RF signals with different frequencies. The generated one or more source RF signals are supplied to the lower electrode and / or the upper electrode. The second RF generating unit 31b is configured to be coupled to the lower electrode via at least one impedance matching circuit to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a frequency lower than that of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may also be configured to generate a plurality of bias RF signals with different frequencies. One or more bias RF signals generated are supplied to the lower electrode. Furthermore, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] Furthermore, the power supply 30 may also include a DC (direct current) power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is configured to be connected to the lower electrode and generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may also be applied to other electrodes, such as the adsorption electrodes in the electrostatic chuck 114. In one embodiment, the second DC generating unit 32b is configured to be connected to the upper electrode and generate a second DC signal. The generated second DC signal is applied to the upper electrode. In various embodiments, at least one of the first and second DC signals may be pulsed. Furthermore, in addition to the RF power supply 31, the first and second DC generating units 32a and 32b may also be provided, and the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0024] The exhaust system 40 may be connected, for example, to a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may also include a pressure regulating valve and a vacuum pump. The pressure regulating valve is used to adjust the internal pressure of the plasma processing space 10s. The vacuum pump may also include a turbomolecular pump, a dry vacuum pump, or a combination thereof.

[0025] The control unit 2 processes commands that can be executed by a computer that enables the plasma processing apparatus 1 to perform the various processes described herein. The control unit 2 may be configured to control various elements of the plasma processing apparatus 1 in a manner appropriate for performing the various processes described herein. In one embodiment, part or all of the control unit 2 may also be included in the plasma processing apparatus 1. The control unit 2 may, for example, include a computer 2a. The computer 2a may, for example, include a processing unit (CPU: Central Processing Unit) 2a1, a memory unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control actions based on programs stored in the memory unit 2a2. The memory unit 2a2 may also include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 can also communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

[0026] <Upper Electrode Assembly> Next, using Figure 1 or Figure 2, the constituent elements of the upper electrode assembly 13, which is the gas diffusion section, and the plasma processing apparatus 1 attached to the upper electrode assembly 13 will be described. Figure 2 is an explanatory diagram showing an enlarged view of a portion of the upper electrode assembly 13. Furthermore, Figure 2 is an enlarged view of a portion (one side of the line symmetry) of the upper electrode assembly 13 in the top plate 10b shown in Figure 1, which has a line symmetry shape relative to the center of its width direction (center line O in the figure).

[0027] As shown in Figure 2, the upper electrode assembly 13 functions as a gas diffuser, which constitutes part or all of the top plate 10b of the plasma processing chamber 10, allowing at least one processing gas to diffuse and be introduced into the plasma processing space 10s. The upper electrode assembly 13 includes a gas diffuser plate 120, an upper electrode plate 130, and an insulating plate 140. The upper electrode plate 130 is disposed between the gas diffuser plate 120 and the insulating plate 140, and these plates are stacked in the vertical direction. The gas diffuser plate 120 has at least one first gas supply port 13c for a first gas and at least one second gas supply port 14c for a second gas. Furthermore, at least one gas diffusion space 13b, serving as the space for main gas diffusion, can also be formed in the gas diffuser plate 120. Furthermore, at least one gas diffusion space 14b, serving as the space for additional gas diffusion, can also be formed in the gas diffuser plate 120. That is, the upper electrode assembly 13 has a gas diffuser plate 120, an upper electrode plate 130, and an insulating plate 140 in sequence from top to bottom.

[0028] The gas diffuser plate 120 is formed of a first conductive material. In one embodiment, the first conductive material is Al (aluminum). The upper electrode plate 130 is formed of a second conductive material. The second conductive material is different from the first conductive material. In one embodiment, the second conductive material is Si (silicon). The insulating plate 140 is formed of an insulating material. In one embodiment, the insulating material is quartz. The insulating plate 140 has a surface exposed below the plasma processing space 10s (plasma exposure surface). A plurality of first gas introduction paths 13a are formed in the upper electrode plate 130 and the insulating plate 140, extending through their thickness direction (vertical direction). The first gas introduction paths 13a are connected to the gas supply section 20 via the gas diffuser space 13b and the gas supply port 13c. A gas supply outlet 13d is formed in the gas diffuser plate 120. The main gas diffused in the gas diffusion space 13b is introduced into the plasma processing space 10s via the gas outlet 13d, through the first through hole 13e formed inside the upper electrode plate 130, and the gas inlet hole 13f formed in the insulating plate 140. That is, the first gas introduction path 13a has a gas outlet 13d, a first through hole 13e, and a gas inlet hole 13f, and is configured to introduce the main gas of the autonomous gas supply unit 20a into the plasma processing space 10s in the future. In one embodiment, the upper electrode plate 130 is disposed between the gas diffusion plate 120 and the insulating plate 140. Furthermore, the upper electrode plate 130 has a plurality of first through holes 13e and a plurality of second through holes 14e. The plurality of first through holes 13e are connected to at least one first gas supply port 13c via the gas diffusion space 13b and the gas outlet 13d of the gas diffusion plate 120. A plurality of second through holes 14e are connected to at least one second gas supply port 14c via the gas diffusion space 14b and gas outlet 14d of the gas diffuser plate 120.

[0029] The number or configuration of gas introduction paths is arbitrary. Besides the first gas introduction path 13a described above, other gas introduction paths may also be provided. For example, as shown in FIG2, a second gas introduction path 14a, including a gas outlet 14d, a second through hole 14e, and a gas introduction hole 14f, may also be provided. It may also be configured to introduce an additive gas different from the main gas into the plasma processing space 10s from the gas diffusion space 14b and the gas supply port 14c. A mixed gas containing multiple gases may also be introduced from the second gas introduction path 14a. Furthermore, although not shown in FIG1 and 2, a third gas introduction path and a fourth gas introduction path may also be provided. Moreover, details regarding the number or configuration of the gas introduction paths (gas introduction holes) opening on the lower surface of the insulating plate 140 in this embodiment will be described below with reference to the drawings.

[0030] An electromagnet unit 15 with a coil 15a inside is disposed on the upper part or above the plasma processing chamber 10. In one embodiment, the electromagnet unit 15 is generally circular when viewed from above. The electromagnet unit 15 is configured to generate a magnetic field within the plasma processing chamber 10 by passing current through the coil 15a from an external current source (not shown). Furthermore, the power supply 30 shown in FIG1 can also be used as the power supply for the electromagnet unit 15. Various configurations can be applied to the electromagnet unit 15. For example, the configuration described in Patent Document 1 can also be applied to the electromagnet unit 15.

[0031] A refrigerant flow path (not shown) may also be provided on the gas diffuser 120 for the flow of a heat transfer fluid, such as brine or gas circulating between the device and a cooler outside the device. The refrigerant flow path may, for example, regulate the temperature of the insulating plate 140, which is subject to temperature variations due to plasma heating. For example, the refrigerant flow path may also be located inside the upper electrode plate 130, and a metal plate containing the refrigerant flow path may also be located on the upper part of the gas diffuser 120.

[0032] The insulating plate 140 is disposed to cover the lower surface of the upper electrode plate 130. At least two annular protrusions protruding downwards are formed on the lower surface of the insulating plate 140. In one embodiment, as shown in FIG2, an inner annular protrusion 142 and an outer annular protrusion 144 are formed on the lower surface of the insulating plate 140. Both the inner annular protrusion 142 and the outer annular protrusion 144 have an annular shape when viewed from above. When viewed from above, the diameter of the inner annular protrusion 142 is smaller than the diameter of the outer annular protrusion 144. When viewed from above, a portion or all of the outer annular protrusion 144 may also overlap with the central region 111a (substrate support surface) of the substrate support portion 11 used to support the substrate W.

[0033] As described above, a plurality of gas introduction paths (e.g., gas introduction path 13a, gas introduction path 14a) are formed through the insulating plate 140, each corresponding to a gas introduction hole (e.g., gas introduction hole 13f, gas introduction hole 14f). The detailed positional relationship and configuration of these plurality of gas introduction holes with the inner annular protrusion 142 and outer annular protrusion 144 formed on the lower surface of the insulating plate 140 will be described below. Furthermore, the insulating plate 140 may have not only the aforementioned gas introduction holes 13f and 14f, but also, as described below, a gas introduction hole 175 with an arbitrary configuration.

[0034] <First Embodiment of the Insulating Board> Figure 3A is a schematic diagram illustrating the structure of the insulating plate 140 according to the first embodiment, showing an enlarged view of a portion of it (one side of the linearly symmetrical shape). Figure 3B is a schematic plan view of the insulating plate 140 according to the first embodiment. As shown, the insulating plate 140 has an inner annular protrusion 142 and an outer annular protrusion 144 protruding downwards from the lower surface, formed sequentially from the inner side. In one embodiment, the radial width W2 of the outer annular protrusion 144 may also be greater than the radial width W1 of the inner annular protrusion 142. In one embodiment, the protrusion dimension H2 of the outer annular protrusion 144 may also be greater than the protrusion dimension H1 of the inner annular protrusion 142. By making the width or protrusion dimension of the outer annular protrusion 144 greater than the width or protrusion dimension of the inner annular protrusion 142, the area to be removed during the manufacturing of the insulating plate 140 is reduced, thereby improving manufacturability.

[0035] In one embodiment, one or both of the inner annular protrusion 142 and the outer annular protrusion 144 have a generally rectangular shape. Here, the term "generally rectangular shape" can also refer to a circular shape obtained by chamfering the corners of the lower surface side of the rectangular shape in cross-section, as shown in FIG3. Furthermore, in one embodiment, one or both of the inner annular protrusion 142 and the outer annular protrusion 144 may also be generally semi-circular in cross-section.

[0036] By forming an inner annular protrusion 142 and an outer annular protrusion 144 on the insulating plate 140, the region where the inner annular protrusion 142 and the outer annular protrusion 144 are formed is thicker than other regions. In this way, the plasma density is increased near the center of the plasma processing space 10s, that is, the center of the substrate W, thereby improving the uniformity of the plasma processing.

[0037] The insulating plate 140 has a plurality of first gas inlet holes 150 formed on the inner annular protrusion 142. Each first gas inlet hole 150 is connected to at least one first gas supply port 13c via any of the plurality of first through holes 13e. In one embodiment, the plurality of first gas inlet holes 150 are arranged at equal intervals in the circumferential direction along the circumference of a first circle having a first diameter. The first gas inlet holes 150 may also be formed near the inner wall 151 of the inner annular protrusion 142. When the inner annular protrusion 142 is circular or approximately semi-circular in cross-section, by forming the first gas inlet holes 150 near the inner wall 151, gas flow is formed in the inward direction relative to the plasma processing space 10s. The first gas inlet hole 150 is connected to the gas outlet of the gas diffuser plate 120 (e.g., gas outlet 13d shown in FIG2), and introduces the main gas into the plasma processing space 10s. In one embodiment, a plurality of the first gas inlet holes 150 overlap with the substrate support surface 111a of the substrate support portion 11 when viewed from above (see FIG10, 11).

[0038] The insulating plate 140 has a plurality of second gas inlet holes 160 formed on the outer annular protrusion 144. Each second gas inlet hole 160 is connected to at least one first gas supply port 13c via any of the plurality of first through holes 13e. In one embodiment, the plurality of second gas inlet holes 160 are arranged at equal intervals in the circumferential direction along a circumference of a second circle having a second diameter greater than the first diameter. The second gas inlet holes 160 are connected to the gas outlet of the gas diffuser plate 120 (e.g., gas outlet 13d shown in FIG. 2) to introduce the main gas into the plasma processing space 10s. In one embodiment, the plurality of second gas inlet holes 160 overlap with the substrate support surface 111a of the substrate support portion 11 when viewed from above (see FIG. 10, 11).

[0039] The insulating plate 140 has a plurality of third gas inlet holes 170 formed outside the second gas inlet hole 160. Each third gas inlet hole 170 is connected to at least one second gas supply port 14c via any of the plurality of second through holes 14e. In one embodiment, the plurality of third gas inlet holes 170 are arranged at equal intervals in the circumferential direction along a circumference of a third circle having a third diameter larger than the second diameter. The third gas inlet holes 170 may also be formed at the base end 171 outside the outer annular protrusion 144. The third gas inlet holes 170 are connected to the gas outlet of the gas diffuser plate 120 (e.g., the gas outlet 14d shown in FIG. 2) to introduce added gas into the plasma processing space 10s. In one embodiment, the plurality of third gas inlet holes 170 do not overlap with the substrate support surface 111a of the substrate support portion 11 when viewed from above (see FIG. 10, 11).

[0040] Furthermore, in one embodiment, as shown in Figures 3A and 3B, the insulating plate 140 may further have a gas inlet hole 175 in addition to the first gas inlet hole 150, the second gas inlet hole 160, and the third gas inlet hole 170. The arrangement or number of gas inlet holes 175 is arbitrary. For example, as shown in the figures, they may be formed inside the inner annular protrusion 142 and between the inner annular protrusion 142 and the outer annular protrusion 144.

[0041] Referring to Figures 3A and 3B, an example of the positional relationship or configuration of the inner annular protrusion 142 and the outer annular protrusion 144 or the gas inlet holes formed in the insulating plate 140 has been described, but the scope of the present invention is not limited thereto.

[0042] <Second Embodiment of Insulating Board> Figure 4 is a schematic diagram illustrating the structure of the insulating plate 140 in the second embodiment. As shown in Figure 4, in one embodiment, the position of the third gas inlet hole 170 may also be outside the outer annular protrusion 144.

[0043] <Third Embodiment of Insulating Board> Figure 5 is a schematic diagram illustrating the structure of the insulating plate 140 in the third embodiment. As shown in Figure 5, in one embodiment, the third gas inlet hole 170 may also be provided on the outer annular protrusion 144.

[0044] <Fourth Embodiment of the Insulating Board> Figure 6 is a schematic diagram illustrating the structure of the insulating plate 140 according to the fourth embodiment. As shown in Figure 6, in one embodiment, the third gas inlet hole 170 is provided on the outer annular protrusion 144, and its upper inlet 170a and lower outlet 170b can be at different radial positions. That is, the shape of the third gas inlet hole 170 can also be arbitrarily designed according to the radial width of the outer annular protrusion 144.

[0045] <Fifth Embodiment of the Insulating Board> Figure 7 is a schematic diagram illustrating the structure of the insulating plate 140 according to the fifth embodiment. In one embodiment, as shown in Figure 7, the insulating plate 140 has a plurality of fourth gas inlet holes 180 formed at the inner base end 181 of the outer annular protrusion 144. Each fourth gas inlet hole 180 is connected to at least one first gas supply port 13c via any of the plurality of first through holes 13e. In one embodiment, the plurality of fourth gas inlet holes 180 are arranged at equal intervals in the circumferential direction along the circumference of a fourth circle having a fourth diameter that is larger than the first diameter and smaller than the second diameter. Fourth gas inlet holes 180 formed at the inner base end 181 of the outer annular protrusion 144 may also be provided. The fourth gas inlet hole 180 is connected to the gas outlet of the gas diffuser plate 120 (e.g., the gas outlet 13d shown in Figure 2) to introduce the main gas into the plasma processing space 10s.

[0046] <Sixth Embodiment of the Insulating Board> Figure 8 is a schematic diagram illustrating the structure of the insulating plate 140 according to the sixth embodiment. As shown in Figure 8, in one embodiment, an additional outer annular protrusion 186 protruding downward from the lower surface of the insulating plate 140 may be formed radially and outward from the outer annular protrusion 144. In one embodiment, the radial width W3 of the additional outer annular protrusion 186 may also be greater than the width W2 of the outer annular protrusion 144. The protrusion dimension H3 of the additional outer annular protrusion 186 may also be greater than the protrusion dimension H2 of the outer annular protrusion 144. Here, the third gas inlet hole 170 may also be formed at the outer base end 188 of the additional outer annular protrusion 186.

[0047] <Seventh Embodiment of the Insulating Board> Figure 9 is a schematic diagram illustrating the structure of the insulating plate 140 in the seventh embodiment. As shown in Figure 9, in the insulating plate 140 of the sixth embodiment, the third gas inlet hole 170 may also be provided on the additional outer annular protrusion 186.

[0048] <Method for processing substrates using a plasma processing device> Next, an example of a processing method for the substrate W in the plasma processing apparatus 1 configured as described above will be explained. Furthermore, in the plasma processing apparatus 1, various plasma treatments such as etching, film formation, and diffusion are performed on the substrate W.

[0049] First, the substrate W is moved into the plasma processing chamber 10 and placed on the electrostatic chuck 114 of the substrate support 11. Next, a voltage is applied to the adsorption electrodes of the electrostatic chuck 114, thereby adsorbing and holding the substrate W on the electrostatic chuck 114 by electrostatic force.

[0050] If the substrate W is held by the electrostatic chuck 114, the internal pressure of the plasma processing chamber 10 is then reduced to a vacuum environment. Next, processing gas is supplied to the plasma processing space 10s from the gas supply unit 20 via the upper electrode assembly 13. Furthermore, RF power for plasma generation is supplied from the first RF generation unit 31a to the upper or lower electrode, thereby exciting the processing gas and generating plasma. Alternatively, bias RF power can be supplied to the lower electrode from the second RF generation unit 31b. Then, in the plasma processing space 10s, plasma processing is performed on the substrate W by the action of the generated plasma.

[0051] At this time, a magnetic field is generated in the plasma processing space for 10 seconds by means of the electromagnet unit 15. Furthermore, as described above, by forming an inner annular protrusion 142 and an outer annular protrusion 144 on the insulating plate 140, the uniformity of the plasma processing is improved. Also, in the case where an additive gas is introduced into the plasma processing space for 10 seconds in addition to the main gas during plasma processing, by better designing the configuration of the gas inlet holes, the additive gas is prevented from flowing back to the center of the substrate W.

[0052] When plasma processing ends, the supply of source RF power from the first RF generation unit 31a and the supply of processing gas from the gas supply unit 20 are stopped. When bias RF power is supplied during plasma processing, the supply of bias RF power is also stopped.

[0053] Next, the electrostatic chuck 114 is stopped from adsorbing and holding the substrate W, and the substrate W and the electrostatic chuck 114 are destaticated after plasma treatment. Then, the substrate W is detached from the electrostatic chuck 114 and removed from the plasma treatment apparatus 1. In this way, the series of plasma treatments is completed.

[0054] <The effects and functions of the technology of this invention> In the above embodiments, for example, an inner annular protrusion 142 and an outer annular protrusion 144, as shown in FIG3, are formed on the lower surface of the insulating plate 140. This increases the plasma density in a specific region of the plasma processing space 10s, for example, in the central portion of the substrate W, thereby improving the uniformity of the plasma processing. That is, it aims to improve the uniformity of the plasma processing on the substrate W.

[0055] Furthermore, in the above embodiments, a plurality of gas inlet holes are provided on or at the base of each of the protrusions, such as the inner annular protrusion 142, the outer annular protrusion 144, and the additional outer annular protrusion 186, formed on the lower surface of the insulating plate 140. This allows for a better modification of the gas distribution of the main gas or additive gas introduced into the plasma processing space 10s, thereby improving the uniformity of the plasma processing on the substrate W. For example, by providing a third gas inlet hole 170 outside the second gas inlet hole 160, the additive gas introduced from the third gas inlet hole 170 is prevented from flowing back towards the center of the substrate W.

[0056] For example, as shown in FIG10, when a third gas inlet hole 170 is formed at the base end 171 outside the outer annular protrusion 144 (refer to FIG3 and FIG7), the added gas or mixed gas introduced from this location flows toward the vicinity of the periphery of the substrate W and its outer side, as shown by P1 in FIG. That is, the outer wall of the outer annular protrusion 144 becomes a wall, suppressing the added gas or mixed gas from flowing back to the vicinity of the center of the substrate W, thereby improving the controllability of gas flow.

[0057] Furthermore, as shown in Figure 11, when the second gas inlet hole 160 is formed on the outer annular protrusion 144 (refer to Figures 3-9), the flow P1 of the additive gas or mixed gas introduced from the third gas inlet hole 170 is blocked by the flow P2 of the processing gas introduced from the second gas inlet hole 160, and the backflow to the vicinity of the center of the substrate W is suppressed. Also, when the first gas inlet hole 150 is provided on the inner annular protrusion 142, the backflow of the aforementioned gas flow P1 or P2 to the vicinity of the center of the substrate W is suppressed by the flow P3 of the processing gas introduced from this location.

[0058] Furthermore, for example, as shown in FIG12, by providing an inner annular protrusion 142 and an outer annular protrusion 144, as shown in P4, the flow of processing gas introduced from any gas inlet hole 175 formed between these protrusions will not concentrate in the vicinity of the central portion of the substrate W. Also, as shown in FIG13, a second gas inlet hole 160 is formed on the outer annular protrusion 144, as shown in P5, for introducing processing gas. In this way, the outward escape of processing gas introduced from any gas inlet hole 175 formed between the protrusions (P4 in the figure) can be suppressed by the air curtain effect. That is, by the presence of the wall accompanying the formation of the protrusions or the air curtain effect, free radicals (neutral particles) are concentrated in the central portion of the substrate W, thereby improving the uniformity of plasma processing.

[0059] Furthermore, in the above embodiments, the case in which a plurality of gas inlet holes are provided on the lower surface of the insulating plate 140 included in the upper electrode assembly 13, where an inner annular protrusion 142 and an outer annular protrusion 144 are formed, is described. However, the scope of the present invention is not limited to this. The present invention can be applied to the exposed surface (hereinafter referred to as the exposed surface) of the upper electrode assembly 13 included in the plasma processing apparatus 1 that is exposed to plasma.

[0060] When the upper electrode assembly 13 has an exposed surface on its lower surface, serving as a plasma exposure surface, this exposed surface may also have the following configuration: In one embodiment, an inner annular protrusion 142 and an outer annular protrusion 144 protruding downwards may be formed on the exposed surface. In another embodiment, a plurality of first gas inlet holes 150 communicating with at least one first gas supply port 13c may be formed on the inner annular protrusion 142 of the exposed surface. In yet another embodiment, a plurality of second gas inlet holes 160 communicating with at least one first gas supply port 13c may be formed on the outer annular protrusion 144 of the exposed surface. Furthermore, in one embodiment, a plurality of third gas inlet holes 170 communicating with at least one second gas supply port 14c may be formed outside the second gas inlet holes 160 of the exposed surface.

[0061] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The above embodiments do not depart from the scope and spirit of the appended patent applications and may be omitted, substituted, or modified in various forms.

[0062] 1: Plasma treatment device 2: Control Department 2a: Computer 2a1: Processing Department 2a2: Memory Department 2a3: Communication Interface 10: Plasma treatment chamber 10a: Sidewall 10b: Top plate 10e: Gas exhaust outlet 10s: Plasma processing space 11:Substrate support department 13: Upper electrode assembly 13a: First gas introduction path 13b: Gas diffusion space 13c: First gas supply port 13d: Gas supply outlet 13e: First through hole 13f: Gas inlet port 14a: Second gas introduction path 14b: Gas diffusion space 14c: Second gas supply port 14d: Gas outlet 14e: Second through hole 14f: Gas inlet port 15: Electromagnet Unit 15a: Coil 20: Gas Supply Department 20a: Main Gas Supply Department 20b: Add gas supply unit 21: Gas Source 21a: Main gas source 21b: Add a gas source 22: Flow controller 22a: Flow controller 22b: Flow controller 30: Power supply 31: RF power supply 31a: First RF Generation Unit 31b: Second RF Generation Unit 32: DC power supply 32a: First DC Generation Unit 32b: Second DC Generation Unit 40: Exhaust System 111: Ontology Department 111a: Central Region 111b: Annular region 112: Ring Component 113:Abutment 114: Electrostatic Chuck 120: Gas diffuser plate 130: Upper electrode plate 140: Insulation board 142: Inner annular protrusion 144: Outer annular protrusion 150: First gas inlet hole 160: Second gas inlet port 170: Third gas inlet hole 170a: Upper entrance 170b: Lower outlet 171: Outer base end 175: Gas inlet port 180: 4th gas inlet port 181: Inner base end 186: Added outer annular protrusion H1: Protruding Dimensions H2: Protruding dimensions H3: Prominent Dimensions W: substrate W1: Width W2: Width W3: Width

Claims

1. A plasma treatment apparatus, comprising: a plasma treatment chamber; A substrate support portion disposed within the plasma processing chamber; a lower electrode disposed within the substrate support portion; at least one RF power supply coupled to the lower electrode; and an upper electrode assembly disposed above the substrate support portion; the upper electrode assembly includes: a gas diffusion plate having at least one first gas supply port for a first gas and at least one second gas supply port for a second gas; and an insulating plate; The upper electrode plate is disposed between the gas diffusion plate and the insulating plate, and has a plurality of first through holes communicating with the at least one first gas supply port and a plurality of second through holes communicating with the at least one second gas supply port; the insulating plate has an inner annular protrusion and an outer annular protrusion protruding downward from its lower surface, all or part of the outer annular protrusion overlapping the substrate support surface of the substrate support portion when viewed from above, the width of the outer annular protrusion being greater than the width of the inner annular protrusion, and the insulating plate having a plurality of first gas inlet holes, which are formed on the inner annular protrusion, and each first gas inlet hole communicating with the at least one first gas supply port via any of the plurality of first through holes; A plurality of second gas inlet holes are formed on the outer annular protrusion, and each second gas inlet hole is connected to the at least one first gas supply port via any one of the plurality of first through holes; and a plurality of third gas inlet holes are formed outside the second gas inlet holes, and each third gas inlet hole is connected to the at least one second gas supply port via any one of the plurality of second through holes.

2. The plasma treatment apparatus of claim 1, wherein the plurality of first gas inlet holes are formed near the inner wall of the inner annular protrusion.

3. The plasma processing apparatus of claim 1, wherein the protrusion dimension of the outer annular protrusion is greater than the protrusion dimension of the inner annular protrusion.

4. The plasma processing apparatus of claim 3, further comprising an electromagnet unit disposed on the upper part or above the plasma processing chamber.

5. The plasma processing apparatus of claim 4, wherein the insulating plate is formed of quartz and the upper electrode plate is formed of aluminum.

6. The plasma processing apparatus of claim 5, wherein one or both of the inner annular protrusion and the outer annular protrusion have a generally rectangular shape in cross-section.

7. The plasma processing apparatus of claim 6, wherein one or both of the inner annular protrusion and the outer annular protrusion have a circular shape formed by chamfering the corners of a rectangular shape when viewed in cross-section.

8. The plasma processing apparatus of claim 5, wherein one or both of the inner annular protrusion and the outer annular protrusion have a generally semi-circular shape when viewed in cross-section.

9. The plasma processing apparatus of claim 1, wherein the plurality of third gas inlet holes are formed at the outer base end of the outer annular protrusion, and the insulating plate further has a plurality of fourth gas inlet holes, which are formed at the inner base end of the outer annular protrusion, and each fourth gas inlet hole is connected to the at least one first gas supply port via any of the plurality of first through holes.

10. The plasma treatment apparatus of claim 1, wherein the plurality of third gas inlet holes are formed on the outer annular protrusion.

11. The plasma processing apparatus of claim 1, wherein the insulating plate further has an additional outer annular protrusion that protrudes downward from its lower surface and surrounds the outer annular protrusion, and the plurality of third gas inlet holes are formed at the outer base end of the additional outer annular protrusion.

12. The plasma processing apparatus of claim 1, wherein the insulating plate further has an additional outer annular protrusion that protrudes downward from its lower surface and surrounds the outer annular protrusion, and the plurality of third gas inlet holes are formed on the additional outer annular protrusion.

13. The plasma processing apparatus of claim 11, wherein the protrusion dimension of the additional outer annular protrusion is greater than the protrusion dimension of the outer annular protrusion.

14. A plasma treatment apparatus comprising: a plasma treatment chamber; A substrate support portion disposed within the plasma processing chamber; a lower electrode disposed within the substrate support portion; at least one RF power supply coupled to the lower electrode; and an upper electrode assembly disposed above the substrate support portion; the upper electrode assembly includes: a gas diffusion plate having at least one first gas supply port for a first gas and at least one second gas supply port for a second gas; and an insulating plate; The upper electrode plate is disposed between the gas diffusion plate and the insulating plate, and has a plurality of first through holes communicating with the at least one first gas supply port and a plurality of second through holes communicating with the at least one second gas supply port; the insulating plate has an inner annular protrusion and an outer annular protrusion protruding downward from its lower surface; the insulating plate has a plurality of first gas inlet holes, which are formed on the inner annular protrusion, and each first gas inlet hole is connected to the at least one first gas supply port through any of the plurality of first through holes; A plurality of second gas inlet holes are formed on the outer annular protrusion, and each second gas inlet hole is connected to the at least one first gas supply port via any of the plurality of first through holes; and a plurality of third gas inlet holes are formed outside the second gas inlet holes, and each third gas inlet hole is connected to the at least one second gas supply port via any of the plurality of second through holes. The insulating plate further has an additional outer annular protrusion that protrudes downward from its lower surface and surrounds the outer annular protrusion. The plurality of third gas inlet holes are formed at the outer base end of the additional outer annular protrusion. The width of the additional outer annular protrusion is greater than the width of the outer annular protrusion.

15. A plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an upper electrode assembly disposed above the substrate support; and a plasma generating unit configured to generate plasma in a space between the substrate support and the upper electrode assembly; the upper electrode assembly having: at least one first gas supply port for a first gas; at least one second gas supply port for a second gas; and an exposed surface exposed to the plasma; the exposed surface having: an inner annular protrusion and an outer annular protrusion protruding downwards; and a plurality of first gas inlet holes formed on the inner annular protrusion, each first gas inlet hole communicating with the at least one first gas supply port; A plurality of second gas inlet holes are formed on the outer annular protrusion, and each second gas inlet hole is connected to the at least one first gas supply port; and a plurality of third gas inlet holes are formed outside the second gas inlet holes, and each third gas inlet hole is connected to the at least one second gas supply port. All or part of the outer annular protrusion overlaps with the substrate support surface of the substrate support portion when viewed from above. The plurality of first gas inlet holes are formed near the inner wall of the inner annular protrusion. The width of the outer annular protrusion is greater than the width of the inner annular protrusion.

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